Classify the following pairs of lines as coincident, parallel or intersecting:

(i) 2x + y – 1 = 0 and 3x + 2y + 5 = 0


(ii) x – y = 0 and 3x – 3y + 5 = 0


(iii) 3x + 2y – 4 = 0 and 6x + 4y – 8 = 0

Let a1x + b1y + c1 = 0 and a2x + b2y + c2 = 0 be the two lines.


(a) The lines intersect if is true.


(b) The lines are parallel if is true.


(c) The lines are coincident if is true.


(i) Given: 2x + y − 1 = 0 and 3x + 2y + 5 = 0


Explanation:


Here,


Therefore, the lines 2x + y − 1 = 0 and 3x + 2y + 5 = 0 intersect.


(ii) Given: x − y = 0 and 3x − 3y + 5 = 0


Explanation:


Here,


Therefore, the lines x − y = 0 and 3x − 3y + 5 = 0 are parallel.


(iii) Given: 3x + 2y − 4 = 0 and 6x + 4y − 8 = 0


Explanation:


Here,


Therefore, the lines 3x + 2y − 4 = 0 and 6x + 4y − 8 = 0 are coincident.


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